A number of reports on microbial conversion of macrolide antibiotics have been presented hitherto. Eiki et al. reported 9-deacylation of 9-acetyljosamycin using Streptomyces olivochromogenes (J. Ferment. Bioeng., 71, 370-372 (1991)). Omura et al. summarized 4"-deacylation of 16-membered macrolide antibiotics (J. Antibiotics, 28, 401-433 (1975)). Although 16-membered macrolide antibiotics include a number of antibiotics having an acyl group at the 3-position such as leucomycins, spiramycins, deltamycins and carbomycins, microbial 3-deacylation of these antibiotics has never been reported so far. In addition, none of the compounds provided by the present invention represented by formulae (III), (IV) and (V) shown below has been reported as a natural or synthetic compound.
It is very difficult to eliminate a 3-acyl group of a 16-membered macrolide antibiotic through a chemical reaction or with the use of an intracellular enzyme. In addition, it is known that the MIC (minimum inhibitory concentration) of a 3-deacylated substance on a gram-positive bacterium is usually lower than that of the starting compound. Therefore, it is highly important to provide a 3-deacylated derivative of a 16-membered macrolide antibiotic in order to develop a novel and useful macrolide antibiotic or to give a material to be converted into the same.